Cartridge



p 1967 H. STADLER ETAL 3,339,487

CARTRIDGE Filed Jan. 6, 1965 FIG. 2

INVENTORS.

HANS STADLER HEINZ GAWLICK HANS UMBACH ATTOR YS.

United States Patent 7 Claims. (cl. 102-41 The present invention relates to a cartridge, and more particularly to a cartridge made of plastic material for firing over short distances.

The prior art proposal, represented by German Patent 341,991, to manufacture in one piece the bullet and cartridge case with an infantry cartridge consisting of metal and to create by a corresponding dimensioning of the wall thickness between the bullet and cartridge case a definite separating zone, has reached a few years back new significance, and more particularly for practice ammunition of the type illustrated in German Patent 1,146,785 for firing over short distances. More particularly, it has been proposed on the basis of and by the use of the aforementioned unitary, one-piece construction, to make the cartridge case and bullet of plastic material particularly of plastic resinous material. Of course, for firing over longer distances such a cartridge would not be usable by reason of the smaller mass of the bullet; however, for firing over short distances, a surprisingly high firing accuracy resulted with the use of such plastic bullets.

Even though the experiences and tests with cartridges of this type were very good, certain objections and difiiculties arose especially with certain automatic weapons. In contrast to metals, the plastic material is not of stable or permanent shape, above all under the influence of the high temperatures occurring during the firing. The cartridge case expands and under certain circumstances abuts against the cartridge chamber so securely that the ejector of the gun is unable to pull the same out. The jamming or wedging can even go so far that the ejector tears off the cartridge bottom whereas the cartridge case remains stuck in the cartridge chamber. The gun then fails completely resulting in misfiring. Hence, the problem arose to construct the cartridge in such a manner that such a jamming or wedging will be avoided.

It is necessary for the comprehension of the present invention to say a few words about the construction of a target cartridge. The plastic part is composed of three parts, namely the case part, the bullet part and a neck part connecting the case with the bullet. The neck part thereby has a smaller diameter than the cartridge case. At the transition from the neck part to the cartridge case a step is provided whereas at the transition from the neck part to the bullet the wall thickness is so chosen that a definite separating zone occurs thereat. During firing, the bullet separates in this zone from the cartridge case with its neck portion.

The aforementioned aim to avoid the wedging or jamming of the cartridge case in the cartridge chamber is made possible according to the present invention by a novel construction of the neck part, and more particularly in that a number of bursting grooves extending in the direction of the cartridge axis are worked or formed into the neck portion. If with such a construction the propellent gas pressure occurs in the neck portion, which leads to the separation of the bullet, then the bursting grooves tear open. These grooves act in a manner of a number of valve apertures through which the propellent gases reach the outside of the neck part. The strips into which the neck part is subdivided by the tearing open of the bursting grooves no longer are subjected to the one- "ice sided or unilateral high internal pressure but are acted upon on both sides approximately by the same pressure. The occurrence of an abutment pressure is thereby avoided, which might lead to the aforementioned shortcomings and failures, namely to a getting stuck 0f the cartridge case in the chamber or tearing off of the neck part.

Since the gas pressure has the possibility to pass over to the outside of the neck part, a high pressure is exerted on the shoulder between the neck part and the cartridge case which is effective assistingly in the direction of the ejection of the cartridge.

The inventive concept can also be extended to the cartridge case in such a manner that the bursting grooves extend beyond the shoulder over the case, appropriately up to within proximity of the bottom piece. The effect of the pressure relief thereby takes place practically over the entire length of the case and the neck part.

Accordingly, it is an object of the present invention to provide a unitary cartridge made of plastic material which avoids the aforementioned shortcomings and drawbacks encountered with the prior art constructions.

Another object of the present invention resides in the provision of a plastic cartridge for practice ammunition consisting of integrally formed bullet, neck portion and cartridge case which assures with certainty the absence of jamming or sticking of the cartridge case and/or neck portion in the cartridge chamber.

A further object of the present invention resides in the provision of a unitary plastic cartridge, especially for practice ammunition, which assures proper operation even when using semi-automatic or automatic weapons.

Still another object of the present invention resides on the provision of a plastic cartridge made in one piece and consisting of bullet and cartridge case which may be readily manufactured in such a manner as to avoid the aforementioned shortcomings.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein:

FIGURE 1 is an elevational view of a cartridge in accordance with the present invention prior to firing thereof, one-half of the cartridge being shown in axial cross section,

FIGURE 2 is an elevational view of the cartridge case of FIGURE 1 after firing thereof,

FIGURE 3 is a partial cross sectional view, in a plane transverse to the cartridge axis, through the neck portion of a cartridge in accordance with the present invention, and

FIGURES 4 and 5 are partial cross sectional views. similar to FIGURE 3, of two further modified embodiments of cartridge cases in accordance with the present invention.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, the cartridge illustrated in FIGURE 1 is made with the bullet part 1, the neck part 2 and the cartridge case 3 thereof in one piece and of plastic material. Any suitable known plastic material may thereby be used. The bottom piece 4 together with the primer consists of metal and is clamped to or connected in a conventional manner with the open end of the case 3 by an elastic formlocking connection. The separating zone between neck part 2 and bullet part 1 is indicated by reference numeral 5. The neck part 2 passes over into the cartridge case 3 by way of a shoulder 6.

A plurality of bursting grooves 7 are formed into the 3 neck part 2 which extend from the separating zone 5 up to the shoulder 6. The embodiment illustrated in FIGURE 1 also shows the further development of the present invention, namely that the bursting grooves 7 are extended beyond the shoulder 6 over the cartridge case jacket 3 up to within proximity of the bottom piece 4.

The condition of the cartridge part remaining in the cartridge chamber after the firing can be seen from FIG- URE 2. As may be seen from this figure, the bursting grooves 7 and 8 are torn open by the pressure produced during the firing. The developed gas has therefore the possibility of passing from the cartridge inside to the outside thereof.

Various cross sectional forms of the neck part 2 and/ or cartridge case part 3 are described by referenc to FIGURES 3 to 5.

In the embodiment according to FIGURE 3, the bursting grooves 10 are made as web portions between two thickened or reinforced portions 11. Six bursting grooves 10 are assumed in this embodiment.

In a similar manner the bursting grooves 10 are formed in the embodiment of FIGURE 4 by the web portions 12. The reinforced portions 13, however, have in this embodiment approximately the shape of a fish-belly.

In the embodiment of FIGURE 5, the Web portions 14 forming the bursting grooves 10- are disposed between the thickened or reinforced portions 15 in such a manner that they form a part of the boundary of the inner diameter which in this case is polygonal.

While we have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art, and we therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are incompassed by the scope of the appended claims.

We claim:

1. A cartridge for firing over short distances, comprising a one-piece structure of plastic material and in cluding a substantially tubular cartridge case, a. bullet portion and a substantially tubular neck portion connecting the cartridge case with the bullet portion, propellant powder within said cartridge case, a bottom piece closing the rearward end of said cartridge case, means effectively constituting between the rearward end of the bullet ,portion and the forward end of the neck portion a separating zone where the bullet portion separates from the neck portion upon firing of the cartridge, and means in said neck portion effectively constituting a plurality of throughout their lengths and quickly release the gases produced by the ignition of said propellant powder for equalizing the pressure within said cartridge case and outside said cartridge case immediately after said bullet portion separates from said neck portion.

2. A cartridge for firing over short distances, according to claim 1, including an abutment shoulder being provided between said neck portion and said cartridge case, the latter being of larger diameter than said neck portion,

the bursting grooves extending by way of said abutment shoulder at least over a substantial portion of the cartridge case.

3. A cartridge provided according to claim 1, wherein said bursting grooves extend over the cartridge case up to within proximity of the bottom piece.

4. A cartridge for firing over short distances, according to claim 1, wherein the bursting grooves are constituted by relatively thinwalled web portions between adjacent reinforced material portions.

5. A practice cartridge according to claim 1, wherein said bursting grooves extend forwardly to the separating zone to produce a plurality of forwardly unconnected strips upon firing of the cartridge.

6. The cartridge of claim 1, wherein one of the two parts consisting of the neck portion and the cartridge case has reinforced material portions and adjacent thin-Walled web portions defining said bursting grooves and forming an interior polygonal cross-sectional shape with the reinforced portions constituting the polygon sides and the web portions constituting flattened 01f end faces of the poly on.

7. A cartridge for firing over short distances, according to claim 6, including an abutment shoulder being provided between said neck portion and said cartridge case, the latter being of larger diameter than said neck portion,

the bursting grooves extending by way of said abutment shoulder at least over a portion of the cartridge case.

References Cited UNITED STATES PATENTS 3,146,712 9/1964 Maurer et a1 10241 FOREIGN PATENTS 1,269,442 7/ 1961 France.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

R. F. STAHL, Assistant Examiner, 

1. A CARTRIDGE FOR FIRING OVER SHORT DISTANCES, COMPRISING A ONE-PIECE STRUCTURE OF PLASTIC MATERIAL AND INCLUDING A SUBSTANTIALLY TUBULAR CARTRIDGE CASE, A BULLET PORTION AND A SUBSTANTIALLY TUBULAR NECK PORTION CONNECTING THE CARTRIDGE CASE WITH THE BULLET PORTION, PROPELLANT POWDER WITHIN SAID CARTRIDGE CASE, A BOTTOM PIECE CLOSING THE REARWARD END OF SAID CARTRIDGE CASE, MEANS EFFECTIVELY CONSTITUTING BETWEEN THE REARWARD END OF THE BULLET PORTION AND THE FORWARD END OF THE NECK PORTION A SEPARATING ZONE WHERE THE BULLET PORTION SEPARATES FROM THE NECK PORTION UPON FIRING OF THE CARTRIDGE, AND MEANS IN SAID NECK PORTION EFFECTIVELY CONSTITUTING A PLURALITY OF BURSTING GROOVES SUBSTANTIALLY EXTENDING IN THE DIRECTION OF THE CARTRIDGE AXIS OPERABLE TO READILY BURST OPEN THROUGHOUT THEIR LENGTHS AND QUICKLY RELEASE THE GASES PRODUCED BY THE IGNITION OF SAID PROPELLANT POWDER FOR EQUALIZING THE PRESSURE WITHIN SAID CARTRIDGE CASE AND OUTSIDE SAID CARTRIDGE CASE IMMEDIATELY AFTER SAID BULLET PORTION SEPARATES FROM SAID NECK PORTION. 